The present invention relates to an apparatus. More specifically, the present invention relates to exercise equipment. Even more specifically, the present invention relates to exercise and rehabilitation equipment for the lower limb system.
By isolating the lower limb system using the apparatus of the present invention, one optimizes muscle strength when physical activities such as standing, walking, sprinting, jumping, cycling and climbing are performed.
One problem with prior exercising apparatus is that it failed to allow weight or resistance to be placed on the lower limb system in a way that allows it to function optimally.
The following research articles address how the lower limb system functions, when attempting specific body movements, for example, standing, walking, sprinting, jumping, cycling and climbing, which are targets of the apparatus of the present invention.
In normal human gait, the lower limb system, composed of the flexor and extensor muscle groups of the hip, knee and ankle, are active when in motion. However, one uses a different amount of force in each muscle group to go/from standing to walking, to running, cycling or climbing. Scientific tests have been performed to analyze the amount of force exerted by each muscle group when they participate in performing such movements. It was found that each muscle group generates a certain amount of force that changes over time when one stands, walks, runs, jumps and cycles.
Suzuki, S., Watanabe, S. and Homma, S., EMG Activity and Kinematics of Human Cycling Movements at Different Constant Velocities, Brain Research, Volume 240 (1982), pg. 245–258, studied the activity of the rectus femoris, biceps femoris, and gastrocnemius muscles in cyclists. They found that activation time of each muscle was far more advanced when achieving maximum speeds than their flexor counterparts (vastus medius of the thigh and tibialis anterior of the leg). Earlier activation times where also seen in the aforementioned muscle groups of extension relative to the flexors. The biarticulate muscle groups of extension thus demonstrated greater significance when accelerating to maximal speeds in cycling.
Jacobs, Bobbert, Van Ingen Schenau et al, studied explosive leg extension movements, namely jumping and sprinting, and their report was published in Brain Research in 1982. They demonstrated a major difference in work done by biarticulate extensors and flexors. They found that the hamstrings in the subjects contributed 7% work in jumping and 11% work in sprinting. This data indicates that these muscle groups are significant in eliciting such movements. The rectus femoris and gastrocnemius muscles, however, contributed 21% and 25% in jumping and 31% and 28% in sprinting, respectively. With greater contribution to work, the latter muscle groups appear to be the most important workhorses.
Van Ingen Schenau et al, in another study of torque effects in extension, compared biarticulate extensors to monoarticulate extensors of the lower limbs and found different effects between the two muscle groups.
Studies examining the amount of power generated by the extensors of the thigh and leg, independent of one another, were also performed.
Wretenberg, Power and Work Produced in Different Leg Muscle Groups When Rising From a Chair, European Journal of Applied Physiology and Occupational Physiology, Volume 68, (1994), pg. 413–417, tested the power and work output of the thigh extensors in individuals who were asked to stand from a seated position. They found that the extensors of the hip and knee demonstrated the greatest amount of power and work for this movement.
Van Soest et al simulated the action of the gastrocnemius as a biarticulate muscle and as a monoarticulate muscle in a computer program to see if in fact biarticulate muscles generated a more critical response at the knee and ankle when one leaps. They concluded that biarticulate muscle stimulation yields a higher vertical leap than monoarticulate muscle groups (the human body is a well build organism).